On K-03 specifically, i cannot say. In general, i have investigate converting a few Esoteric digital pieces...and they have always required buying a new transformer from Esoteric. It is not a matching of just flipping switches internally, or 'moving the taps' which is a fairly straightforward rewiring of the existing transformer.
AGain, cannot say if K-03 is similar, but i have inquired about P70, P-03 and P-01 in the past. Good luck.